A portion of this disclosure contains material in which copyright is claimed by the applicant. The applicant has no objection to the copying of this material in the course of making copies of the application file or any patents that may issue on the application, but all other rights whatsoever in the copyrighted material are reserved.
The present invention relates generally to systems and methods for controlling and monitoring a variety of systems, using modular object-oriented control software which is operated in a local controller associated with the controlled system, and centrally controlled, monitored, and updated using a communications network such as the Internet. These systems and methods are particularly useful in Building Automation Systems (BAS) applications.
In the past, control systems such as building automation systems have typically been proprietary single manufacturer solutions, or complex integrations of independent systems. There have been efforts in the industry to define standards so that such systems can be integrated more effectively, but no truly uniform approach has been made available.
The release of the BACnet/LonMark(trademark) fieldbus communication standards for building automation systems have initiated a rethinking of building automation system architectures that is likely to revolutionize the control solution landscape. Traditional proprietary building automation architectures perform well, but they are expensive to design and install, cumbersome to reconfigure, and often require reams of software to integrate the stand-alone facility services. By contrast, in a distributed BACnet/LonMark fieldbus architecture, logic processing is encapsulated into autonomous multi-vendor modules that communicate among themselves through standard software to cooperatively solve a building control problem. However, in known building automation architectures, the external interface characteristics of devices that are added to the control system must be entered into the database representation of the device""s external interface characteristics before the BAS can effectively control the new device.
Distributing control in this way is expected to minimize installation wiring, optimize control software, lower operating/maintenance costs, and simplify system expansion. In today""s competitive global marketplace, users need the fieldbus""s flexible, reusable and cost-effective building control solutions to respond quickly to changes in facility management services.
There have been advances in other areas of computing which have, however, not been applied in a satisfactory manner to the field of building automation systems. For example, computer systems standards have developed to simplify the cost and development requirements to program systems. Primary technologies include object-oriented software, the Java(trademark) Virtual Machine (JVM) and JavaBeans(trademark).
Object-oriented programming provides a new way to model real-world entities more directly as software building blocks that match the real world better than conventional programming mechanisms. This new software paradigm has an increasing impact on the software realm, in the same way the microprocessor has impacted hardware design and functionality.
In object-oriented programming, application programs are created from self-contained building block modules (objects). Rather than reinventing the wheel every time they create a new program, application engineers can borrow pre-written application modules from a library and simply plug them in. By using object libraries, developers can concentrate on linking appropriate objects together and writing any custom objects that their applications require. Custom objects, in turn, can be added to the library for future reuse.
Networking standards have also developed in an effort to simplify the cost and development requirements to integrate systems. Primary technologies developed in the building automation industry include American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) Building and Control Network (BACnet(trademark)), and the ECHELON LONTALK(trademark) protocol (developed by Echelon Corporation of Palo Alto, Calif.).
Meanwhile, in the computer industry, there have been efforts to develop communications standards, although again, these standards have not been applied in any truly effective way to the specific problems of building automation. For example, the goal of the Internet/WWW/Java/CORBA standards is to provide the information the user wants, without taking into account what kind of program to use, what computer it runs on, or the format of the information.
Through a system of hypertext, users of the Web have been able to select and view information from all over the world. However, the basic Web lacks true interactivityxe2x80x94real-time, dynamic, and visual interaction between the user and application. Java brings this missing interactivity to the Web. With a Java-enabled Web browser, the user can encounter animation and interactive applications.
Efforts to implement real time control systems over the Internet have generally been unsuccessful, because of variability in packet transit times and the lack of guaranteed delivery over the Internet.
In conclusion, control systems have historically been based primarily on proprietary technologies of a single manufacturer. Although there have been efforts to standardize these architectures, they have achieved only limited success. The inventors believe that there is a need for a highly integrated standard in the field of control systems which integrates a Java-based common object model, specially adapted for use in building automation applications, and provides central control and monitoring using communications network standards such as the internet
Therefore, it is a general object of the present invention to provide a control system and methods using object-oriented software that integrates BACnet, LonMark, CORBA, Java and Internet systems into a common object model. The present invention in a preferred embodiment uses object technology as a key to constructing truly distributed applications in a multi-vendor open system environment supporting multiple industry standards. The BACnet/LonMark/Internet/CORBA architectures are combined in the invention and Java object-oriented software concepts are applied to effectuate distributed control and information management. Messages (events) are passed between the autonomous modules that use object-technology to encapsulate both data and functionality. These functional objects are replicated for reuse, and are grouped to form more complex functions that build on the work of other objects. The Web BAS Server""s navigational tools provide a global view of the process that is being controlled by the autonomous fieldbus modules and provide unrestricted information flow.
It is a further general object of the present invention to provide a control system and methods in which both pre-defined objects and user-defined and created objects exist in a single control system. A customized programming language is provided for object modification, creation, and management. A set of pre-defined objects is also provided.
It is a still further general object of the present invention to provide a control system and methods that maintains the integrity of system data in a distributed system, and that distributes system data as required throughout the distributed system, through the use of archiving and synchronization techniques. A master copy of each datum is preferably maintained at a single virtual machine, and a system of synchronized and nonsynchronized caches is used to ensure that objects of the control system have access to current system data. System data is archived in order to provide persistency.
It is a still further object of the present invention to provide a control system and methods in which object properties associated with a device are updated dynamically to reflect external interface characteristics of the device. To accomplish this, devices of the control system are queried for their external interface characteristics and their associated object properties updated accordingly. This provides for management of devices without requiring a pre-programed specific external interface representation.
These as well as other objects of the present invention are apparent upon inspection of this specification including the appendices and drawings.